The slider you shove with your hip to get open.

Why the slider went bad

Patio doors fail differently from windows, because you use them. A window gets opened a few times a summer. A slider gets opened every day for twenty years by everyone in the house, often with a foot or a hip, usually while carrying something.

What actually goes wrong is nearly always one of four things. The rollers flatten or seize, so the door drags instead of gliding. The track gets dented or packed with grit, which then chews the new rollers too. The weatherstrip compresses and stops sealing, so you get draughts and dust along the bottom. Or the frame has racked — the door no longer sits square in the opening, which is why it catches at one end of its travel and not the other.

Sometimes you do not need a new door

The first three of those are repairs. New rollers and a track cap, done properly, can bring a fifteen-year-old door back to sliding with one finger, and it costs a fraction of a replacement.

We will tell you when that is what you are looking at. It is a smaller job and a smaller invoice, and we would rather do it than sell you a door you did not need — the fastest way to lose the window job on the rest of the house is to oversell the door.

Replacement is the honest answer when the frame is out of square, when the glass seal has failed and the unit is fogging, when the frame is aluminium and you are replacing the windows around it anyway, or when the door is single-pane. That last one matters more than people expect: a patio door is the largest single piece of glass in most houses, so on a west-facing wall it is doing more to heat your living room in August than any window in the place.

Sliding, French, or something wider

Milgard builds patio doors in three of the lines we carry.

V300 Trinsic in sliding, with the same slim frame as the windows — the choice when the door is mostly there to be looked through.

V400 Tuscany in sliding or French swinging. The French option is the one people picture when they say “patio doors” — two hinged panels that open into or out of the room rather than sliding past each other. It costs more, it needs swing clearance, and on a covered patio it is worth it.

A250 aluminium in sliding, for the narrowest frame and the biggest single panel — with the same energy-code caveat that applies to aluminium windows.

If the opening is wider than a standard two- or three-panel door, or you want the wall to disappear entirely, you are into moving glass walls, which is a different conversation and usually a structural one.

Swapping a slider for French doors

Usually possible in the same opening, and it is one of the more satisfying changes you can make to a room. Two things to know first. You lose the full opening width — a hinged pair needs a frame member down the middle where a slider has none. And you need somewhere for the panels to go: a French door swinging inwards eats about two and a half feet of floor on each side, which is furniture you may have to move permanently.

We will measure the swing before you commit, not after.

Glass, hardware and the permit question

Patio doors take the same low-E glass packages as the windows, which matters because of the sheer area. Tempered glass is standard in doors. Hardware runs from the standard SmartTouch handle up to decorative and upgrade sets, keyed or unkeyed, in a range of finishes — all of it in the brochure below.

On permits: whether the job needs one depends on its scope and on which jurisdiction you are in. A like-for-like door in an existing opening is treated differently from widening the opening or changing the structure. We follow building and safety regulations and file where one is required.

The catalog

Configurations, hardware finishes and door colours are in Milgard’s own brochure: Milgard Patio Doors (PDF, 2.6 MB). The rest of the range is on our Milgard series page, and the doors are on the floor in our Canoga Park showroom — worth sliding one before you choose, since how a door feels in the hand is most of what you are buying.